Ioannis Tsarmantidis

As a freelancer, I support a shipyard (2 accounting entities) in data-driven quality assurance in the SAP S/4HANA MM environment. The focus is on the analysis and validation of an already completed S/4HANA migration of material master data and material-related master data: Using a Python tool, I perform success and plausibility checks, identify deviations and recurring error patterns, and verify findings directly in SAP/Fiori. Based on this, I define reconciliation rules (e.g., for material structure and views), derive root causes, and implement corrective actions. In parallel, I am preparing the expansion to an additional accounting entity, analyzing material structures, and supporting object/field mapping as well as template maintenance in Migration Cockpit/LTMOM, including test runs and re-runs. For the analysis, I connect source systems such as AS400 and CADMATIC as well as data from previous migrations and provide the results in a Power BI Dashboard; I am currently expanding this with an integrated Python script for automated checks and SAP drill-downs for root cause analysis. Technologies: SAP S/4HANA (Fiori), Python (pandas), Power BI (Power Query), AS400, CADMATIC, Excel/CSV, LTMOM.

As a freelancer, I support a hospital group (21 accounting entities) at the interface of audit, finance analytics, and SAP S/4HANA Public Cloud. I accompany the PwC-side IT audit/annual financial statement audit (requirements, data extracts, traceability, closing) and document existing migrations and interfaces in runbooks, processes, and QA checks. Operationally, I plan, configure, and execute DB-to-DB or Migration Cockpit runs (incl. LTMOM) for FI (G/L accounts, open items A/R & A/P), AA, CO, BP, and MM, and develop scripts/tooling for automation, logging, and re-runs. For data quality, I implement Fiori-based completeness and plausibility checks, log analyses, and correction loops, combining Python/Alteryx with HANA SQL staging and performance optimization. A focus is on cross-system open item analyses: consolidated OP reconciliations, automated export from Diamant, and Diamant/Navision evaluations up to Power BI dashboards with KPIs and deviations. Additionally, I optimize EMR integrations (xViaNova Navision incl. YTD logic, validation, audit logging, notifications, and sync concept) and standardize further EMR systems via templates, documentation/enablement, and API/SFTP/CSV transfers. Technologies: SAP S/4HANA Public Cloud (Fiori), Python (pandas), Alteryx, HANA SQL/SQLScript, Power BI, Diamant, Navision, xViaNova, API/SFTP/CSV, Git, Docker.

While working at PwC Germany, executed end-to-end migrations from SAP R/3 and diverse legacy systems to SAP S/4HANA Cloud. Utilised SAP Migration Cockpit, HANA SQL Script, bespoke ETL routines, Alteryx Designer workflows and Python (pandas) scripts for data profiling, cleansing, deduplication and reconciliation of datasets. Deliverables reduced migration defects and cycle time, enabling on-schedule go-lives and avoiding costly rework for clients and PwC.